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How many wires does RS485 use?
RS485 needs 3 conductors and a shield. Many people say it’s a two-wire network but it is not. Two conductors are used to carry the RS485 Differential voltage signal.
Is RS485 a 2 wire?
The RS485 network is wrongly referred to as a “2 wires plus shield” network. It is not. The 2 wires are sometimes referred as “+” and “-” instead of “A” and “B”, making the user think that 2 wires is all you need to make it work. But these are signal wires and the network always requires a return path.
How do I connect two RS485 devices?
For 2-wire transmission, you will need to short the transmit (TXD) and receive (RXD) signals together on the RS-485 port. Refer to Set Up 2-Wire (Half-Duplex) Communication with RS-485 Port for the pinouts and more details.
What is difference between RS485 and Modbus?
Is Modbus the same as RS485? The answer is no, because both of these are relative concepts that need each other in order to fulfil their purposes. Modbus defines the protocol type and RS485 defines the signal level on the protocol.
What is difference between Modbus and RS485?
Is RS485 faster than RS232?
Data Transmission Speed RS232 is more than able to perform for a short distance and low data speed requirements. RS232 has a transmission speed of 1Mb/s up to 15M. However, RS485 has a data transmission speed of up to 10Mb/s for a distance of 15M. At the maximum of 1200M, RS485 transmits at 100Kb/s.
What kind of wiring is used for RS-485?
Regardless of the communication device, the wiring connections are the same. RS-485 communication is done with 2-wire connections that connect A and B ports on the meter (s) to A and B ports on the communication device. To connect a single meter you simply wire the A port on the meter to the A port on the communication device.
What does twisted pair mean in RS-485?
As its name implies, a twisted pair is simply a pair of wires that are of equal length and are twisted together. Using an RS-485-compliant transmitter with twisted-pair wire reduces two major sources of problems for designers of high-speed long-distance networks: radiated EMI and received EMI.
What kind of grease to use on RS-485 cable?
Each RS-485 connection will use one of the twisted pairs. Shielded cable protects the communications in electrically noisy environments. When making wire connections it is a good idea to apply dielectric grease to the connection points. Because CAT5/6 wires are so small the connections can easily become corroded and unreliable over time.
Do you need termination for a 485 connection?
First check the pinout connections and specifications of the devices you want to connect in 485 connection. Termination is not required for baud rates 19.2K or lower at distances up to wires, set Switch 4 up to ON for half duplex operation (no echo). Switch 3 down/OFF=No